class C {
	int n;
	static int sum=0;
	void setN(int n) {
	   this.n=n;
	}
	int getSum() {
	   for(int i=1;i<=n;i++)
	      sum=sum+i;
	   return sum;
	}
}
public class E4_3 {
	public static void main(String args[]) {
	   C b1=new C(),b2=new C();
	   b1.setN(3);
	   b2.setN(5);
	   int s1=b1.getSum();
	   int s2=b2.getSum();
	   System.out.println(s1+s2);
	}
}